title: Comparison of magnetic resonance imaging of inhaled SF6 with respiratory gas analysis.
abstract: Magnetic resonance imaging of inhaled fluorinated inert gases ((19)F-MRI) such as sulfur hexafluoride (SF(6)) allows for analysis of ventilated air spaces. In this study, the possibility of using this technique to image lung function was assessed. For this, (19)F-MRI of inhaled SF(6) was compared with respiratory gas analysis, which is a global but reliable measure of alveolar gas fraction. Five anesthetized pigs underwent multiple-breath wash-in procedures with a gas mixture of 70% SF(6) and 30% oxygen. Two-dimensional (19)F-MRI and end-expiratory gas fraction analysis were performed after 4 to 24 inhaled breaths. Signal intensity of (19)F-MRI and end-expiratory SF(6) fraction were evaluated with respect to linear correlation and reproducibility. Time constants were estimated by both MRI and respiratory gas analysis data and compared for agreement. A good linear correlation between signal intensity and end-expiratory gas fraction was found (correlation coefficient 0.99+/-0.01). The data were reproducible (standard error of signal intensity 8% vs. that of gas fraction 5%) and the comparison of time constants yielded a sufficient agreement. According to the good linear correlation and the acceptable reproducibility, we suggest the (19)F-MRI to be a valuable tool for quantification of intrapulmonary SF(6) and hence lung function.
authors.affiliation: Department of Anaesthesiology, Johannes Gutenberg-University, Mainz, Germany. ascholz@uni-mainz.de
authors.forename: Alexander-Wigbert
authors.initials: AW
authors.lastname: Scholz
authors.forename: Ursula
authors.initials: U
authors.lastname: Wolf
authors.forename: Michael
authors.initials: M
authors.lastname: Fabel
authors.forename: Norbert
authors.initials: N
authors.lastname: Weiler
authors.forename: Claus P
authors.initials: CP
authors.lastname: Heussel
authors.forename: Balthasar
authors.initials: B
authors.lastname: Eberle
authors.forename: Matthias
authors.initials: M
authors.lastname: David
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Schreiber
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D001944:Breath Tests / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D008168:Lung / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000379:methods; D013459:Sulfur Hexafluoride / Q000493:pharmacokinetics*; D013552:Swine
chemical_list: D013459:Sulfur Hexafluoride